To reduce a fraction to the lowest terms equivalent: divide the numerator and denominator by their greatest common factor, GCF
To calculate the greatest common factor, GCF:
- 1. Factor the numerator and the denominator (into prime factors), build their prime factorizations.
- 2. Multiply all their common prime factors, taken by the lowest exponents.
1. Factor the numerator and the denominator:
To factor a number (into prime factors) - or, in other words, to break it down to prime factors - or, in other words, to build its prime factorization: find the prime numbers that multiply together to get that number.
The prime factorizations:
Written with exponents:
5,145 = 3 × 5 × 7 × 7 × 7 = 3 × 5 × 73
5,145 is a composite number.
Written with exponents:
1,250,000 = 2 × 2 × 2 × 2 × 5 × 5 × 5 × 5 × 5 × 5 × 5 = 24 × 57
1,250,000 is a composite number.
5,145/1,250,000 =
(5,145 ÷ 5) / (1,250,000 ÷ 5) =
1,029/250,000
Yet another method to reduce the fraction
To reduce a fraction without calculating the GCF: factor its numerator and denominator, then all the common prime factors are easily identified and crossed out.
5,145/1,250,000 =
(3 × 5 × 73)/(24 × 57) =
((3 × 5 × 73) ÷ 5) / ((24 × 57) ÷ 5) =
(3 × 73)/(24 × 56) =
1,029/250,000
As a decimal number:
Simply divide the numerator by the denominator, without a remainder, as shown below:
1,029/250,000 =
1,029 ÷ 250,000 =
0.004116 ≈
0